Wednesday, September 29, 2010

ACLs, knees, and genes

a provocative article in the NY Times projects the possibility that genetics predisposes some - esp women - to NON-CONTACT anterior cruciate ligament (ACL) tears.

tim hewett, of cincinnati children's hospital, a prominent researcher on ACL injury and prevention, reports that one set of twin girls tore their knees up within a year. their older sister also tore her ACL. another set of twin sisters had incurred torn ACLs in high school, as did their dad...and his two triplet brothers!!!! scary huh? suggesting that you can look at your family's knees and see your risk profile in scar tissue.

studies in south africa have found a gene sequence that alters the customary elasticity of ligamentous collagen. interestingly, more women had this aberration whereas males who had had ACL injuries did not have this variant and women who had not torn their ACLs also did not have it.

so, we can now add to the list of predisposing factors - weak, easily-fatiguing, and late-firing hamstrings; weak and delayed-firing gluteus medii; possible femoral notch anatomical variations; and poor training/jumping/cutting technique - genetics. like many things genetics, this does not mean you WILL have an ACL tear if other family members have had one. but it does mean you might want to train properly with more closed chain- squats and lunges - and plyometric - jumping/hopping - and agility - cutting, changing direction - exercises. see a pro who's studied this syndrome, not just one who knows how to build bigger muscles. you need better ones, not bigger ones.


  1. I say strengthen the joints through proper exercise, diet and muscle building supplements. This is the way to avoid injury.

  2. thanks for your shout out. i agree - proper exercise will 'reduce' but not eliminate your risk of knee injury. however, it's wise to recognize that there are no studies that support diet or supplements in doing so. they, at best, support optimal development of muscle via exercise. i think you would admit that many an athlete who eats poorly has avoided ACL injury and that not all who eat well have avoided it. nutrition and supplementation - and i must tell you, i'm not a big fan of the latter - merely provide the building blocks for health and well-being. i say merely because that may not be sufficient to build optimal strength, power, endurance and injury-resistance. good training, however, is essential to do that.


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